The present invention relates to vehicular headlamps. More specifically, the present invention relates to a projection-type vehicular headlamp in which dazzling of the vision of oncoming drivers by light directly emitted from the light source of the lamp is prevented.
In a vehicular headlamp of the projection type, a cut-line forming shade is arranged such that its upper edge is located close to a focal point of a reflector that reflects and condenses light emitted from a light source. The reflected light, some portion of which is cut off by the cut-line forming shade, is projected forwards by a condenser lens. Such a headlamp requires provisions for providing convection of air to protect the reflector from heat, and also it is desired to reduce the weight of the projection unit composed of the light source, reflector, cut-line forming shade, and condenser lens. For these purposes, a recess can be formed in a lens holder used to mount the condenser lens to the reflector, or the lens holder itself can be formed with a ring-like lens holding portion having a plurality of arms and connected to the reflector via the arms. In this arrangement, an opening is formed between the reflector and the condenser lens.
However, if the opening is formed between the reflector and the condenser lens as described above, some of the light directly emitted from the light source passes through the opening. Such light is radiated to the outside without impinging on the condenser lens, resulting in dazzle to the vision of drivers of oncoming vehicles or pedestrians.
If the reflector has an elliptical lower surface, light from the light source bulb emitted toward the lower surface of the reflector is reflected by the reflector and radiated to the outside through the opening between the condenser lens and the reflector. This too can cause a problem of dazzlement.
To solve this problem, an extension can provided which covers the periphery of the projector unit, thus cutting off direct light traveling through the opening. If the extension for covering the periphery of the projector unit is used to prevent dazzlement due to direct beams of light as in the case of the aforementioned vehicular headlamp, it is of course impossible to dispense with the extension. Moreover, the direct light is cut off in regions where it is diffused to some extent. As a result, the necessity of enlarging the extension emerges as another problem.
It is thus an object of the present invention to prevent dazzlement from being caused by beams of light directly emitted from a light source without requiring any bulky component members.
A vehicular headlamp according to the present invention is intended to solve the problems mentioned above. For this purpose, a vehicular headlamp of the invention comprises a light source, a reflector, a cut-line forming shade for forming a cut line, and a condenser lens. The cut-line forming shade cuts off some of the light emitted from the light source and reflected by the reflector and forms shaped beams of light. The condenser lens projects the shaped beams of light forwards and radiates them according to a predetermined light distribution pattern. An opening is formed between the condenser lens and the reflector. A dazzling-light cutting shade for cutting off light emitted toward regions above the light distribution pattern is disposed between the light source and the opening.
Thus, the vehicular headlamp according to the present invention prevent dazzlement from occurring due to light directly emitted from the light source. Also, since the dazzling-light cutting shade is disposed between the light source and the opening, direct beams of light are cut off in regions where they are diffused just slightly. Therefore, no bulky component members are required.